This invention concerns the preparation of warp strands for weaving and more specifically with drawing-in warp strands.
In preparation for weaving, warp strands are drawn through eyes in respective heddles mounted on a heddle frame. U.S. Pat. No. 4,038,729, issued on Aug. 2, 1977 to Franklin L. Townsend, describes an apparatus, and its operation, for accomplishing the selection and positioning of a heddle such that its eye can receive a next successive warp strand from a warp beam during the drawing-in operation. When the heddle is thus positioned according to Townsend's teachings, or by any other means, a needle passing through the eye draws a warp strand through the eye. If, by any chance, a heddle is not present when the needle attempts to insert the warp strand, there would be a resulting error in the warp. Such an error can be corrected by inserting a replacement heddle in proper position on the frame and drawing-in the omitted warp strand. Replacement heddles are heavier than other heddles and for that reason are undesirable on a high speed loom. If a heddle is present, but not properly positioned, the warp strand will not be drawn through the eye. Since the heddle is present, it is only necessary to manually draw the warp strand through the eye. As a result of either of these deficiencies in positioning a heddle, the drawing-in operation must be stopped and someone must take the time necessary to correct the faults produced thereby. Production is therefore impaired and costs are increased.
In the past, someone had to be continuously present in order to immediately detect and correct the fault caused by absence of misalignment of a heddle. This was expensive. As an alternative, the fault would not be detected and corrected until later. The task of correcting the fault was then complicated. Immediate detection and correction of such faults without the continuous presence of someone to accomplish such results was obviously desirable.